Neurosurgery Blog

Childs Nerv Syst (2010) 26:19–28 DOI 10.1007/s00381-009-0990-8

This study described a 23-year experience in the treatment of children with pilocytic astrocytomas (piloA) with the aim of identifying putative clinical, histopathological, and/or immunohistochemical features that could be related to the outcome of these patients.

Methods Clinical data of 31 patients under 18 years of age with piloA were obtained from 1984 to 2006.

Results The mean age at the time of surgery was 7.8± 4.2 years (1 to 17 years), and the mean follow-up was 5.7± 5.4 years (1 to 20 years). The most common site of tumor formation was the cerebellum (17), followed by brainstem (4), optic chiasmatic hypothalamic region (4), cerebral hemisphere (3), cervical spinal cord (2), and optic nerve (1). Gross total resection (GTR) was achieved in 23 (74.1%), mainly in those with tumors located in the cerebellum and cerebral hemispheres (P=0.02). The global mortality rate was 6.4%. Nine patients were reoperated. Rosenthal fibers, eosinophilic granular bodies, microvascular proliferation, and lymphocytic infiltration were observed in most cases. The mean Ki-67LI was 4.4 ± 4.5%. In all cases, Gal-3 expression in tumor cells was observed with variable staining pattern.

Conclusions Aside from GTR, no other clinical, histopathological, or immunohistochemical features were found to be related to the prognosis. We postulate that strict follow- up is recommended if piloA is associated with high mitotic activity/Ki67-LI, or if GTR cannot be achieved at surgery. Tumor recurrence or progression of the residual lesion should be strictly observed. In some aspects, childhood piloA remains an enigmatic tumor.

Neurosurgery 65:908–913, 2009 DOI: 10.1227/01.NEU.0000356982.82378.BA

Magnetic resonance spectroscopy is widely used in addition to magnetic resonance imaging in the characterization of brain tumors. Compounds containing choline (Cho) have an important role in the evaluation of tumor malignancy. For this purpose, various ratios of Cho and other metabolites, such as creatine (Cr), have been assessed. The aim of this study was to compare normalized mean and maximum levels of Cho as single parameters in the noninvasive grading of gliomas.

METHODS: Proton spectroscopic imaging data of 63 patients with suspected World Health Organization (WHO) grade II or III gliomas were acquired at 3 T. Cho concentrations of the tumor were analyzed by a frequency domain fit and normalized to the corresponding contralateral healthy brain tissue. Metabolite images were used to determine the maximum and mean Cho as well as Cr concentrations of the tumor. Furthermore, contrast enhancement of the tumor was analyzed on standard magnetic resonance imaging. All patients subsequently underwent tumor resection or stereotactic biopsy to confirm diagnosis of glioma. Statistical analysis using the Kruskal-Wallis test, Mann-Whitney U test, and receiver operating characteristic curve analysis was performed with BiAS software (Epsilon Verlag GmbH, Frankfurt, Germany).

RESULTS: Histopathological examinations revealed WHO grades II (n=27), III (n=26), and IV (n=10). There was a statistically significant difference in both normalized maximum and mean Cho between WHO grade II and non-necrotic WHO grade III/IV gliomas (mean, 1.45 ^±0.28 versus 2.16±0.36, P<0.05; maximum, 1.64±0.32 versus 3.32±0.55, P<0.0001). Receiver operating characteristic analyses rendered a 2.02 cutoff value for maximum Cho with a sensitivity and specificity of 86.1% and 77.8%, respectively. For mean Cho, we found a cutoff value of 1.52 (sensitivity, 77.8%; specificity, 63.0%). The diagnostic accuracy of maximum Cho was superior to that of mean Cho and also the ratio of Cho/Cr (82.5% versus 71.4% and 72.1%, respectively), but all 3 parameters were superior to contrast enhancement of the tumor (61.9%).

CONCLUSION: Both maximum and mean Cho differ between low- and high-grade gliomas. Compared with contrast enhancement, mean Cho, and Cho/Cr, maximum Cho of the tumor provides the highest accuracy in discriminating between low- and high-grade tumors, indicating usefulness of this single parameter in the process of therapeutic decision making.

Journal of Clinical Oncology. DOI:10.1200/JCO.2008.19.8721

Purpose

We evaluated the efficacy of bevacizumab (Avastin TM), alone and in combination with irinotecan, in patients with recurrent glioblastoma in a phase II, multicenter, open-label, noncomparative trial.

Patients and Methods

One hundred sixty-seven patients were randomly assigned to receive bevacizumab 10 mg/kg alone or in combination with irinotecan 340 mg/m2 or 125 mg/m2 (with or without concomitant enzyme-inducing antiepileptic drugs, respectively) once every 2 weeks. Primary end points were 6-month progression-free survival and objective response rate, as determined by independent radiology review. Secondary end points included safety and overall survival.

Results

In the bevacizumab-alone and the bevacizumab-plus-irinotecan groups, estimated 6-month progression-free survival rates were 42.6% and 50.3%, respectively; objective response rates were 28.2% and 37.8%, respectively; and median overall survival times were 9.2 months and 8.7 months, respectively. There was a trend for patients who were taking corticosteroids at baseline to take stable or decreasing doses over time. Of the patients treated with bevacizumab alone or bevacizumab plus irinotecan, 46.4% and 65.8%, respectively, experienced grade  3 adverse events, the most common of which were hypertension (8.3%) and convulsion (6.0%) in the bevacizumab-alone group and convulsion (13.9%), neutropenia (8.9%), and fatigue (8.9%) in the bevacizumab-plus-irinotecan group. Intracranial hemorrhage was noted in two patients (2.4%) in the bevacizumab-alone group (grade 1) and in three patients (3.8%) patients in the bevacizumabplus-irinotecan group (grades 1, 2, and 4, respectively).

Conclusion

Bevacizumab, alone or in combination with irinotecan, was well tolerated and active in recurrent glioblastoma.

J Neurosurg Pediatrics 4:199-216, 2009. DOI: 10.3171/2009.3.PEDS08459

Object. The authors undertook this study to review their experience with cortical resections in the rolandic region in children with intractable  epilepsy.
Methods. The authors retrospectively reviewed the medical records obtained in 22 children with intractable epilepsy arising from the rolandic region. All patients underwent preoperative   electroencephalography (EEG), MRimaging, prolonged video-EEG recordings, functional MR imaging, magnetoencephalography, and in some instances PET/SPECT studies. In 21 patients invasive subdural grid and depth electrode monitoring was performed. Resection of the epileptogenic zones in the rolandic region was undertaken in all cases. Seizure outcome was graded according to the Engel classification. Functional outcome was determined using validated outcome scores.
Results. There were 10 girls and 12 boys, whose mean age at seizure onset was 3.2 years. The mean age at surgery was 10 years. Seizure duration prior to surgery was a mean of 7.4 years. Nine patients had preoperative hemiparesis.
Neuropsychological testing revealed impairment in some domains in 19 patients in whom evaluation was possible. Magnetic resonance imaging abnormalities were identified in 19 patients. Magnetoencephalography was performed in all patients and showed perirolandic spike clusters on the affected side in 20 patients. The mean duration of invasive monitoring was 4.2 days. The mean number of seizures during the period of invasive monitoring was 17. All patients underwent resection that involved primary motor and/or sensory cortex. The most common pathological entity encountered was cortical dysplasia, in 13 children. Immediately postoperatively, 20 patients had differing degrees of hemiparesis, from mild to severe. The hemiparesis improved in all affected patients by 3–6 months postoperatively. With a mean follow-up of 4.1 years (minimum 2 years), seizure outcome in 14 children (64%) was Engel Class I and seizure outcome in 4 (18%) was Engel Class II. In this series, seizure outcome following perirolandic resection was intimately related to the child’s age at the time of surgery. By univariate logistic regression analysis, age at surgery was a statistically significant factor predicting seizure outcome (p < 0.024).
Conclusions. Resection of rolandic cortex for intractable epilepsy is possible with expected morbidity. Accurate mapping of regions of functional cortex and epileptogenic zones may lead to improved seizure outcome in children with intractable rolandic epilepsy. It is important to counsel patients and families preoperatively to prepare them for possible worsened functional outcome involving motor, sensory and/or language pathways.

Neurosurg Rev (2009) 32:435–444.DOI:10.1007/s10143-009-0210-8

Trigeminal neurinomas are the second most common intracranial neurinomas next to the vestibular neurinomas. Eighty-four patients with trigeminal neurinomas were treated between 2003 and 2007. There were 40 women and 44 men (mean age 43 years). The most frequent symptoms were headache or numbness of the ipsilateral hemiface. There were 24 type A, nine type B, 45 type C, and six type D tumors. Dextroscope virtual reality technology was used for preoperative planning in recent eight cases. Gross total resection was achieved in 63 patients. We found that the major impediments to complete removal were adherent to the brainstem and skull base vascular structure, the frontotemporal approach with zygomatic or orbitozygomatic osteotomy or subtemporal approach could offer excellent exposure of the middle fossa and access to the posterior fossa, and Dextroscope virtual reality technology was a very useful tool to identify surgical and anatomic nuances and enhance preoperative planning in trigeminal neurinomas resection.

Vini G. Khurana, PhD, FRACS, Charles Teo, MBBS, FRACS, Michael Kundi, PhD, Lennart Hardell, MD, PhD, Michael Carlberg, MSc.

Surgical Neurology Volume 72, Issue 3, Pages 205-214 (September 2009) doi:10.1016/j.surneu.2009.01.019

The debate regarding the health effects of low-intensity electromagnetic radiation from sources such as power lines, base stations, and cell phones has recently been reignited. In the present review, the authors attempt to address the following question: is there epidemiologic evidence for an association between long-term cell phone usage and the risk of developing a brain tumor? Included with this meta-analysis of the long-term epidemiologic data are a brief overview of cell phone technology and discussion of laboratory data, biological mechanisms, and brain tumor incidence.

In order to be included in the present meta-analysis, studies were required to have met all of the following criteria: (i) publication in a peer-reviewed journal; (ii) inclusion of participants using cell phones for ≥10 years (ie, minimum 10-year “latency”); and (iii) incorporation of a “laterality” analysis of long-term users (ie, analysis of the side of the brain tumor relative to the side of the head preferred for cell phone usage). This is a meta-analysis incorporating all 11 long-term epidemiologic studies in this field.

The results indicate that using a cell phone for ≥10 years approximately doubles the risk of being diagnosed with a brain tumor on the same (“ipsilateral”) side of the head as that preferred for cell phone use. The data achieve statistical significance for glioma and acoustic neuroma but not for meningioma.

Conclusion

The authors conclude that there is adequate epidemiologic evidence to suggest a link between prolonged cell phone usage and the development of an ipsilateral brain tumor.

In elderly patients with brain tumors, the prevention of postoperative systemic complications is extremely important, and identification of the risk factors would be useful for planning therapy. The authors investigated ways to avoid postoperative complications by identifying risk factors.

Methods
The study population included 84 patients, 70 years of age or older, who underwent surgical brain tumor removal. The following independent factors were assessed by univariate and multivariate analyses: sex, age, preoperative underlying diseases and complications, histopathological findings, preoperative Karnofsky Performance Scale (KPS) score, preoperative whole blood hemoglobin (Hb) level, preoperative serum total protein (TP) level, operation time, intraoperative blood loss, change in Hb level (difference between pre- and postoperative values), and change in TP level (difference between pre- and postoperative values). The cutoff values for significant independent factors were also determined.

Results
Overall, 35 (41.7%) of the 84 patients had a total of 56 postoperative systemic complications. Univariate analysis identified the preoperative KPS score, intraoperative blood loss, change in Hb level, and change in TP level as risk factors for postoperative complications, and multivariate analysis extracted the following risk factors: the preoperative KPS score (p = 0.0450, OR 4.020), intraoperative blood loss (p = 0.0104, OR 6.571), and change in Hb levels (p = 0.0023, OR 9.301). The cutoff values were: KPS score < 80%, intraoperative blood loss ≥ 350 ml, and change in Hb level ≥ 2.0 g/dl.

Conclusions
In elderly patients with brain tumors, low preoperative KPS score, high intraoperative blood loss, and a large difference between pre- and postoperative Hb levels are significant risk factors for postoperative systemic complications.